Bag manufacture



May I, 1 GURWICK 2,116,571

BAG MANUFACTURE Filed M ay l5, 19156H Viz@ Patented May l0, 1938 iso STATES PATE FFICE BAG i f normen Application May l5, 1936, Serial No. 79,858

3 Claims.

The present invention relates to containers of the bag type and has particular reference to an improvement in bags and other containers constructed of transparent cellulose sheeting and folded into container form with creases or angular edge portions.

A principal object of the invention is the provision of reinforcing means for the creases or edge portions of transparent cellulose sheeting.

An additional object is to provide a bag or similar container which has deposited along the angular edges thereof a reinforcing material composed of a exible non-fibrous cellulose product or the like.

A further object is to provide a method of forming containers having creases or angular edge portions which will not break or shatter as readily as has been the case heretofore.

These and other objects will be evident upon a consideration of the following description of a preferred embodiment of the invention and by reference to the accompanying drawing, inwhich Fig. 1 is a perspective view, somewhat diagrammatic; of a device for applying an integral reinforcing material to a web of transparent cellulose sheeting;

Fig. 2 is a plan view of a satchel bottom bag formed from the web shown in Fig. l, the bag being shown in collapsed condition; and

Fig. 3 is a cross-sectional View taken along line 3-3 of Fig. 2.

In the production of bags and similar types of containers from transparent cellulose sheeting, such as regenerated cellulose and cellulose acetate, it is customary to fold a web of transparent cellulose sheeting into tubular form, to sever bag lengths from the tube, and to fold one end of the tube lengths into closed condition to complete the bag. In such condition the bag is collapsed and the side edges consist of a layer of the transparent cellulose sheeting folded over upon itself and somewhat creased. 'Ihe bottom of the bag likewise consists of several folded-over portions having creases or angular portions. When containers formed of these materials are used, it has been found that breakage of the containers is most apt to occur along these angular or sharp edges or creases.

In accordance with the present invention, the web of transparent cellulose material from which the containers are formed is provided 4with one or more longitudinal strips consisting of a deposit of a exible material of a suciently tough nature to reinforce the containers and to reduce the tendency toward breakage. As shown in Fig. 1,

a web I is taken from a roll of transparent cellulose sheeting I I and thereafter passed through an intaglio printing unit. This unit includes an upper impression roll I2 and a lower edge printing cylinder I3 constructed in the usual 'mannen 5 The lower part of the printing cylinder I3 rotates in a body I4 of the material which it is desired to deposit upon the web as a reinforcing material. The body of material It is carried in a bath I5 and the excess material picked up by 10 the roll I3 is scraped therefrom by means of a doctor blade I6. Cylinder it is an intaglio copper surfaced cylinder having circular etched portions ll and I8 for applying a substantially continuous line of the material in the bath I5, it being understood that the doctor blade I6 scrapes the material from the cylinder i3 except along the etched portions I I and I8.

As a result of passing between the cylinders I2 and I3 the web has deposited thereon longitudi- 20 nally extending stripes I9 and 29 of the material contained in bath I5.l

The material in bath I5 is of the nature of a lacquer ink and includes a. heavy bodied nitrocellulose such as 600 second nitrocellulose. The nitrocellulose is carried in a suitable quick-drying organic solvent which permits the lines of nitrocellulose to be applied and dried quickly before the web is formed into tube lengths. It is characterlstic of nitrocellulose of this type that when so deposited it firmly adheres to the regenerated cellulose or cellulose acetate sheeting of which the web I0 is composed and forms a. relatively thick body portion of a tough nature which resists shattering of the container along the vulnerable t portions covered by the stripes.

After depositing the heavy bodied nitrocellulose stripes, the web is formed into a tube with the stripes I9 and 20 overlapping the edge portions in the manner shown in Fig. 3. That is, the stripes I9 and 20 form a reinforcement for these creased edges that are most likely to be damaged in the use of the bag.

The bag is provided with a Satchel bottom as shown in Fig. 2, the portions of the bottom having the stripes I9 and 20 therealong being folded so that the stripes I9 and 2D meet as substantially shown in the drawing. In this way the 'corners 2| and 22, which are the weakest part of the bottom, are afforded a flexible protection by the stripes I9 and 20, thereby materially increasing the strength of the bag.

As indicated in Fig. 3, the stripes I9 and 20 are printed on the outside surface of the web, but it will be understood that the stripes likewise may be printed on the inside of the web. e invention is applicable to other forms oi containers than the specic bag shown in the drawing. In

general, it will be possible to apply the invern`v tion to any particular form of container or wrapping material by the printing method of the invention. Also, due to the method of application of the stripes i@ and 2@ it is possible to apply stripes other than longitudinal stripes to further protect the material. Thus, a transverse stripe may be applied and a. fold laid along such stripes. In some cases it will be found desirable to print Vwider stripes than shown in the drawing. This facilitates the vertical operation; since it is easier to locate the fold along a wider stripe than along a narrow stripe. The material deposited is a heavy bodied nitrocellulose which produces a substantially thicker lm per unit of material than in the case of lacquer inks employed in intaglio printing of designs. If'desired, the material may be colored to present the appearance of colored stripes on the finished bag or container. Due to the exibility of the printed stripes and the rbody of the material the fold lines of the transparent cellulose sheeting are substantially protected thereby. The nitrocellulose stripes are dierent in their characteristics from the regenerated cellulose and cellulose acetate with which it is desired to employ the material and the comloination of the two types oi' the materials in the manner described materially reduces the shattering tendencies of the containers with which the heavy nitrocellulose is employed. 'I'he improved container is produced at a cost, which is only slightly in excess of the normal cost of the container and the printed stripes not only are protective but are attractive as well, particularly when colored.

Ordinarily, the transparent cellulose web from which the containers are constructed will be sub- Jected to a printing operation and wound into the roll form indicated at ii prior to the operation described hereinabove. That is, the web is sub jected to an ordinary printing operation, wound into roll form, unwound, longitudinal lines of the heavy bodied nitrocellulose are applied to the unwound web, and the web then is folded into container form along the lines of the heavy bodied nitrocellulose. Thus, the protective lines of the heavy bodied nitrocellulose are applied just prior to folding the web into bag form.

It will be recognized that the invention as de? scribed herein is susceptible to modification Without departing from the scope of the appended claims.

I claim:

1. The method of producing containers of transparent cellulose sheeting, which comprises applying longitudinal lines of a quick-drying solution of a heavy bodied nitrocellulose to a traveling web of transparent cellulose sheeting, and folding said web into container form along said lines.

2. The process of making containers, which comprises applying a line of S00 second nitrocellulose contained in a solvent to a web of transparent cellulose sheeting, and folding said web into container form along said line.

3. The process of producing containers of transparent non-brous sheeting, which comprises applying to said sheeting a line of an adherent sointion of .a relatively heavy bodied cellulose compound contained in a relatively quick-drying solvent, drying said solvent, and folding said sheeting along the line of applicationof said cellulose compound.

mVING- GURWICK. 

